Alister Chapman has nice article on his blog which shows the striking difference in the level of image quality between the latest Canon DSLR and an EX1. The Canon of course come off rather poorly, being a stills camera with video, compared to a dedicated video camera.
That’s not to say you can’t get some nice video out of the Canon, but it must be done in a very limited way which maximises it’s only advantage, shallow depth of field. This advantage also just happens to mask most of the image issues by blurring large areas of the picture. Otherwise you end up with a nasty combination of soft images, moire, aliasing and compression artefacts. Combine that with impractical controls in audio, lens functions, ergonomics, paint settings, etc, it becomes a very limiting tool. Beautiful within it’s limit though.